Picked one up on rental from Autozone for $99 - and guess what? - it’s a Mastercool. Looks to be model #MSC-89772. It doesn’t have any markings on it anywhere, but the plastic case UPC number shows the “89772”, so I guess that’s what it is (looks like it on the web). It sells for about $115 delivered. However, the writeups don’t show the plastic case or mention anything about a free 3-in-1 valve (#85530) that are clearly mentioned for models #89660 (or 89661, which superceded -660). Those units can be had for $100 delivered, and may actually be the better deal.
I’ve got a question, though:
I read the PDF manual for the Harbor Freight unit online and it mentions what sounds like a 2nd set of valves on the hose couplings (where you connect to the service ports on the car). They say to turn the thumbwheels clockwise to close (on the manifold), but then they also say to turn these 2nd set of valves counterclockwise to close before connecting to the service ports on the car. Unless I’m missing something, I don’t see this feature on this MasterCool. The couplings have ball bearings and a collar that you can spin around and around, but it doesn’t appear to do anything. Do some units not have these secondary valves? And if so, do I just quickly jam these couplings down on the service port in the car? Won’t there be some leakage as I do this? Seems like there should be a valve where the service port connection is made, and maybe this kit is missing those pieces?